GENERAL HISTOLOGY

Detailed explanation-1: -Examples of echinoderms include sea stars, sea urchins, sea cucumbers, brittle stars, and feather stars (Fig. 3.83). Although they may appear very different, echinoderms all have two major defining characteristics that set them apart from all other animals: a water vascular system and five-sided radial symmetry.

Detailed explanation-2: -Members of the phylum include sea stars (starfish), sea urchins, sea cucumbers, sand dollars, brittle stars, and feather stars.

Detailed explanation-3: -The phylum echinoderms is divided into five extant classes: Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins and sand dollars), Crinoidea (sea lilies or feather stars), and Holothuroidea (sea cucumbers).

Detailed explanation-4: -Echinoderms. Echinoderms are a phylum of marine invertebrates that include starfish, brittle stars, sea cucumbers, sea urchins, sand dollars, and crinoids.

Detailed explanation-5: -Sand Dollars are members of the phylum Echinodermata, and their relatives include sea cucumbers, sea stars and sea urchins among others. Characteristics of this phylum include spiny skin, tube feet for locomotion, and radial symmetry. The flower-like pattern seen on the test of sand dollars is used for gas exchange.